The present invention relates to a standard incorporated into diagnostic and/or quantification tests for antibodies resulting from an infection with a bacterial or viral agent or resulting from an autoimmune or allergic reaction.
The reference materials and standards in the biological field are preparations of substances which have a complex molecular composition involved in quality-control, diagnostic and research mechanisms.
For the diagnosis of the bacterial agents responsible for various infections affecting mammals, including man, various methods have been proposed for obtaining a standardized reference in such a diagnosis.
The agencies dealing with the reimbursement of medical expenses (INAMI) specify that a quantification of immunoglobulins, in particular the quantification of a hypogammaglobulinemia, is distinguished when the total content of immunoglobulins is less than the laboratory standard value. This standard value must be calculated as two measurable standard deviations below the mean associated with controls on the basis of the age bracket or the 95% confidence interval of a control population coupled with age. Consequently, the distinction in a test of diagnosis or quantification of a certain type of antibodies possibly directed against a bacterial agent, must be carried out relative to a standard which is constituted from the laboratory standard value. Consequently, these standards vary very greatly from one laboratory to another, which can falsify the results.
Quataert et al. ((Clinical and Diagnostic Laboratory Immunology Vol. 2 No. 5, pp. 590-597 (September 1995)) describe a method for identifying antibodies specific to each of the serotypes of S. pneumoniae. However, the standard reference batch proposed is obtained from a pool of 17 adults vaccinated with a vaccine preparation, who can present between them an excessive variance, and will necessitate the use of particularly complex mathematical extrapolations for the diagnosis of this bacterial infection. Furthermore, a cross-reactivity between the various capsular antigens of the different serotypes may arise (Coughlin et al., Vaccine 16, No. 18, p. 1761-1767, 1998).
The present invention is directed toward providing an improved standard in diagnostic devices, which is claimed not to have the drawbacks of the prior art, and which can be used to improve the diagnosis, quantification and/or monitoring of immune reactions resulting from infections affecting mammals, including man, in particular resulting from infections by a bacterial or viral agent or resulting from an autoimmune or allergic reaction:
One specific aim of the present invention is to provide a standard in a diagnostic device, which would be of a simple and inexpensive design and which would allow simplification of the diagnosis of such infections without making it necessary to use modifications of the operating protocols for the diagnoses usually used, and more particularly which would not make it necessary to use complex mathematical extrapolations.